File locking

This code:  http://pastebin.com/YaLq1q9L

Results in this:

WindowsError: [Error 32] The process cannot access the file because it is being
used by another process: 'xvid_test.avi'

My naive expectation is that after parsing/extracting metadata,
hachoir would close the file, but it doesn't seem to.

How can I force hachoir to close the file?